8 May
2022
8 May
'22
5:49 a.m.
On Sat, May 7, 2022, 5:19 PM Bakul Shah <bakul(a)iitbombay.org> wrote:
On May 7, 2022, at 12:14 PM, Warner Losh
<imp(a)bsdimp.com> wrote:
We just know the dotted quad world. In the early days of sparse addresses
and crappy name service (or out of date host files) these shortcuts were a
lifesaver.
Warner
10.2 is ambiguous. In a network context, it means, typically,
10.2.0.0/16 (though
your mileage may vary).
In a host context, it means 10.0.0.2. It's
this confusion that has lead
to many efforts
to outright kill this notation.
On FreeBSD:
ping 10.2 tries to ping 10.0.0.2 and
ping 192.168.300 tries to ping 192.168.1.44 (1*2^8+44 == 300)
ping 10.2.300 tries to ping 10.2.1.44
ping 192.1000000 tries to ping 192.15.66.64 (15*2^15+66*2^8+64 == 1000000)
ping 1000000001 tries to ping 59.154.202.1 (59*2^24+154*2^16+202*2^8+1)
ping 300.300 tries to ping 23.217.138.110 (I haven't worked this out!
Prob. a bug)
So the last number is treated as the host number on a given net.
This may have some sense in the classful network world but is
very confusing in the CIDR world.